Time

Quick question: where is yesterday?

I don't mean what happened yesterday. I mean where is it, right now? The actual Tuesday, or whatever it was. Where did it go?

That's today's question, along with three that come attached to it: what "now" is, why time only runs one way, and whether you can travel in it. This is the second of three posts about a theory with some surprising answers. If you missed the first, here's what you need, in about a minute.

Previously

• The universe keeps notes. To know your coffee got colder, you need a note about the earlier sip. Recognition Science, the framework my institute works on, starts from plain facts like that one, and its starting premise is that the world keeps a note of every event, in one shared record, and never changes an old note. We call that record the ledger. If it had a personality, it would be unflappable, extremely thorough, and armed with one response to everything that has ever happened: Noted.
• You're a rhythm. In the theory's smallest model, two tiny clocks pass a token back and forth. Each clock is full (holding the token) or empty. Each tick is flowing, when one clock is full and the other empty, so something moves round the loop between them, or silent, when both are full or both are empty. Silent ticks throw the clocks into guessing, and almost every pattern falls apart that way, like Gary, a drummer who flips a coin before every beat to decide whether to play. (Gary is not getting the gig.) Only four patterns never go silent: the spin, where the token stays put while flow goes round and round, and the swing, where the token hops left, right, left, each starting from either side. What lasts isn't stuff; it's rhythm. And not rhythm in the sense of a heartbeat on a monitor, which can be perfectly regular with nobody home: a lasting rhythm is one that never goes silent.

Two leaps carry over from Part 1: that a person is a pattern of this kind, and that experience lives in the lasting rhythms. The theory hasn't shown either. I also founded the institute, so weigh my enthusiasm accordingly. I'll use two labels to keep things straight. Derived in the model means it follows from the model's rules plus those leaps, worked out in the math behind this series: the preprint it's built on¹ and my institute's follow-up derivations, all shared before independent experts have checked them. Conjecture means it's my bet.

Where is yesterday?

Most of us carry around a picture of time that looks something like this:

The present is the little platform you're standing on. The future rolls in from the front. The past rolls off the back and drops into a bin. Your seventh birthday party: in the bin. The first time you heard your favorite song: bin. The moment you read the word "bin" just now: bin.

We don't look straight at that picture very often. It's a bleak one.

If the ledger is real, the bin doesn't exist. Nothing has ever fallen off the back of the belt. Yesterday is right where it was: every line of it, written down, reading exactly as it did when it was written.

If the ledger is real, the past isn't gone. It's written down, in pen.

Sit with that for a second, because it's stranger than it sounds. Every moment you've lived would still be there, exactly as it happened: the best afternoon of your life, the worst one, the time you laughed so hard you couldn't breathe. Your memories of those moments are copies, and leaky ones. On this picture, the originals are in the ledger, and they haven't faded at all.

Which raises a puzzle of its own. If all of yesterday is still there, what makes today "now"? And why do you remember yesterday and not tomorrow?

What is "now"?

In this theory, "now" is the picture your own record leaves you with: everything the entries so far have pinned down, plus exact odds for everything they haven't. As entries pile up, the picture sharpens into something definite. Then the next entry arrives and it moves on, like instant photos developing one after another.

Notice what "now" holds about the future: odds, and only odds. Think of a coin in mid-air. You can know everything about its odds, 50-50, and still nothing anywhere knows which way it will land. Hang on to that; it decides the time-travel question later.

Why does time only go one way?

You remember yesterday and not tomorrow. Eggs break and don't unbreak. Eggs break for the usual reason, heat and disorder: things spread out and don't spontaneously un-spread. This theory doesn't touch that. What it finds is a second, quieter arrow, built into the ledger itself, in a surprising place.

Start with the lasting rhythms. Film a spin and play it backwards: you see a spin. Film a swing and play it backwards: you see a swing. Watching the lasting rhythms, you couldn't tell which way the film is running. The lasting core has no arrow of its own.

So this arrow lives somewhere else: in everything that isn't lasting, the busy, wobbling surroundings. A whole city of Garys.

Here's how those busy clocks behave. Every clock has a setting that tells it to flip or keep what it's handed, and every setting is a specialist: it's tuned for one kind of tick, makes its move for sure on that kind, and guesses (tosses a coin) on the other. Coin tosses can also leave a clock unsure of its own setting. So at any moment, a busy clock is one of three types:

• a silent specialist: sure of its move on silent ticks;
• a flow specialist: sure of its move on flowing ticks;
• a guesser: it has come out of a coin toss unsure whether it's a flip or a keep, so it tosses a coin on every tick.

And here, straight from the math, is what each kind of tick does to each type:

Follow one clock round: a silent specialist hits a silent tick and becomes a flow specialist; another silent tick makes it guess, and it becomes a guesser; a flowing tick makes it guess again, and it lands as a silent specialist. Back where it started.

Now look at the table and find the move that's missing. Take your time.

It's this one: no tick, of either kind, turns a flow specialist straight back into a silent specialist. The table shows why. A flow specialist only ever changes on a silent tick, and on a silent tick it's out of its depth, so it tosses a coin, and that toss leaves it a guesser. So the trip from silent specialist to flow specialist happens for sure, and the trip straight back never happens at all.

Now run the film backwards. The lap above, reversed, would need exactly that missing move: a flow specialist turning straight back into a silent specialist. So the surroundings' traffic goes round one way, like a roundabout, and nobody had to put up a sign. Nothing outside pushes it: no heat, no special starting condition.

"Yeah, but then the arrow is built into the rules."

In a sense, yes. It's in the basic step, the way the heat arrow is in the laws of heat. Nobody put it there on purpose: the step was set out in an earlier paper, and this arrow only turned up when people worked out what the rules do. But it's there, and if the real world doesn't run on this step, this arrow isn't real. That's the premise again, and it's a fair hit.

If the ledger is right, this arrow lives in your surroundings, not in your core.

The dimmer switch

Now think about what your waking life is plugged into: heartbeat, breath, the itch on your ankle, the to-do list, the hum of the fridge. That's your body's busy activity, and your experience is tied tightly to it. Of course time flows. You're plugged into the part of the world that has an arrow.

So what happens if that link loosens? The theory gives an exact answer, and here's what it actually measures. Hand someone two consecutive moments from a pattern's record, in random order, and ask which came first. For the busy surroundings, they'd be right almost every time. For the lasting core, they could do no better than guessing. And for a mix, their edge over guessing lands exactly in proportion to how much of the pattern is busy.

Derived in the model: the arrow in a mind's own record shrinks in exact proportion to its link to the busy, arrow-carrying activity around it. Halve the link, and you halve the arrow. Cut it, and the arrow is gone. It isn't a wall you fall through. It's a dimmer switch.

(One step is the theory's reading rather than math: that a mind experiences what its own record shows.)

You've had a small taste of this. You look up from something absorbing and two hours have vanished. On this picture, that's a loosened link.

"Yeah, but at the DMV, time doesn't vanish. It crawls."

Right, and that fits too: nothing ties you to every tick of the clock on the wall like a long line with nothing to do.

People who go deep in meditation have long described states that feel timeless. One organization that teaches deep meditation, the Monroe Institute, numbers its states and calls one of them, Focus 15, "no time." That's a description, not a measurement, and a feeling of timelessness could have plenty of explanations. Mine is the dimmer turned all the way down.

There's a twist, and it's the part I find hardest to stop thinking about. With the arrow completely gone, you might expect perfect stillness. You don't necessarily get it. What can be left is a tick-tock with no direction: the swing's token going left, right, left, right. A pendulum is the everyday version. Film it, play it backwards, and nobody can tell, yet it still goes tick, then tock. A clock, it turns out, is not an arrow.

Perfect stillness needs that tick to stop too. The framework calls that state the hub, and the seesaw shows what it means. Put the chance of a step happening forwards on one end, and the chance of the same step happening backwards on the other. While there's an arrow, the seesaw tips: forwards is the heavier side, the first side. Derived in the model: once the arrow is gone and the tick has stopped too, every one of those seesaws in the record sits perfectly level. Each step is exactly as likely backwards as forwards, and swapping the sides, which is just what playing time backwards does, changes nothing. No first side. (It's also the most boring seesaw in the playground, which is sort of the point.)

Here's my leap, flagged: a mind whose record sits perfectly level like that would have no before and after at all. That's the theory's reading of the math, not more math.

Conjecture: that's why deep states feel like "no time," and the hub is the perfect stillness at the bottom of them.

Okay. Time travel.

If the ledger is real, the theory gives clear answers to three questions, and leaves one wide open.

Your body, back to the past: no. The ledger only ever adds lines at the end. Arriving in the past would mean adding events to lines that are already written, and nothing ever changes a written line.

Knowing which future will happen: no. Remember the coin in mid-air. Everything the present contains about what comes next is a set of exact odds, and that isn't a gap that cleverness could close. Nothing in the coin knows which way it will land.

Sensing the possible futures: not ruled out. Nothing is written in the future yet, but its odds are part of the present. The shape of the possibilities, the menu without the order, could in principle be picked up. You can read the whole menu. You can never see the order, because it hasn't been placed.

Reading the past: not ruled out. The past isn't somewhere you'd have to go. It's still here, every line, reading exactly as it did when it was written. The question is whether anything can read it. By a reading I mean any way of getting information back out of the ledger: a question put to the record, and an answer that comes back. Noticing your coffee got colder is a tiny one. Here's what the model supplies for a bigger one:

1. The past is all still there. Not a copy, not a reconstruction: the actual entries.
2. Nothing in the model forbids reading it.
3. The reader has no arrow. The part of you that would do the reading, the lasting rhythm, has no before and after built in.
4. There's a place to read from. The timeless state, dimmer all the way down.

What the model doesn't say is whether any mind ever performs such a reading. That's the open piece, and it's the one the test at the end of this post is for.

So why can't everyone meditate their way back to last Tuesday?

The address problem

From perfect stillness alone, every past moment looks the same; that's what "no before and no after" means. It's like being handed the greatest library ever built and finding that every book has the same plain cover and no title. Everything is in there. You just can't find anything. Very peaceful. Useless for research.

To pull out one particular moment, you'd need two more things: a reading that changes from moment to moment, and an address for the moment you want. The snag: the framework counts time in cycles of eight ticks (that comes from elsewhere in the framework), and then the cycle starts over. As an address system, an eight-tick cycle is a street with only eight house numbers. After 8 you're back at 1. Your mail is a disaster, and good luck finding one particular afternoon in 1993.

What you'd need is an address that never repeats.

Here's one. Picture two drummers who start on the same beat. One hits once a second. The other hits once every 1.618... seconds, the number called the golden ratio. Why that number? Try a simpler one first. If the second drummer hit every 1.5 seconds, then after 3 seconds both would land together again, and from there every pattern would repeat. Mail disaster, again. That happens with any ratio that's a fraction, like 3/2. The golden ratio is never a fraction: its digits run on forever without falling into a repeating pattern, and no fraction can do that. So these two drummers come close to landing together, over and over, like two people trying to high-five while walking past each other forever, but they never do.

That's what makes it an address. Each time the second drummer hits, it lands a different distance past the first drummer's last beat: 0.62 of a beat, then 0.24, then 0.85, then 0.47, then 0.09, and on and on, never the same twice. Every beat comes with its own stamp, and the golden ratio spreads the stamps out as evenly as any number can.

And the drummers don't stop. Beats that haven't happened yet already have their stamps waiting. Dial the future's number and nobody's home: the address exists, and nothing is written there yet.

Whether the physical world actually provides such an address, along with the changing reading that goes with it, is open. So is the hardest question: how a mind would lock onto one.

The part of the past with your name on it

For one part of the past, though, the address problem turns out to be already solved. Yours.

Derived in the model: your own present rhythm, together with the length of your own record, picks out every moment of your past. Nothing from outside is needed.

Think of a diary where you write exactly one page a day. If you know today's page number, you can turn to any day of your life by counting back. You don't need anyone's help. Somebody else's diary is another story: to find their Tuesday you'd need to know when they started, and nothing in your own diary can tell you that.

The math adds one condition. The body's input nudges your rhythm, and every nudge throws the count off by exactly that much. With the body's input gone, the count back is exact. Which raises the question families ask at 3 a.m.: does your rhythm keep running after you die? That deserves more than a footnote, and it's what Part 3 is about.

So of everything that has ever happened, the part of the past easiest to reach would be your own.

Where I land

Feelings and stories don't settle any of this. What would settle it is someone bringing back checkable facts they couldn't have known beforehand. Here's a test that would do it, so you can hold me to it.

Take a thousand moments from the past that are documented but obscure, say the front page of a small-town newspaper on a randomly chosen date, sealed in envelopes nobody involved has seen. Someone in a deep, timeless state tries to describe each one. Judges who don't know which description goes with which envelope match each description to one of five sealed candidates, so pure guessing gets 20% right. (Nobody has to check what state the describer was in. The envelopes don't care how a description was produced.) If the hit rate comes in at 25% or better over the thousand, and other teams can repeat it, something is reading the past. If it sits at 20%, I'd stop saying what I'm about to say.

Which is this: I'm betting reading the past is likely possible. Nothing has shown it. My honest reason is that the deepest pieces it needs (a past that's still there, a reader with no arrow, a timeless place to read from) turned up in the math for other reasons, and none of them was put there for this. And when we went looking for the last piece, an address for your own past, the math handed it over. That's a reason to bet, not a finding.

Conjecture: time travel means reading the past, never visiting it, and sensing the possible futures, never the actual one.

So, where is yesterday? If the ledger is real, it's right where you left it, every line, in pen. Your body can't go back, and nobody can know which future arrives. But the past would still be there to be read, if anything can read it, and the easiest part to reach would be the part with your address on it: your own.

Next time, in Part 3: what happens when a mind lets go of the body? In deep meditation, out of the body, and at the very end.